Applies to:
@RISK 6.x and Up, Professional and Standard Editions
@RISK for Project 4.x

 

Large Right Skew on Project Finish Date

Issue: Even if individual project segments have symmetric distributions, the project’s final finish date may show a strong right skew.

Cause: Predecessor–successor links can truncate distributions:

• If Task A must finish before Task B starts, any distribution on Task B’s start is truncated left.

• This truncation accumulates across tasks, creating a right-skewed finish date.

Solution:

• Review your project’s dependencies.

• Insert Predecessor and Successor columns in the Project sheet to see how links affect distributions.

Tip: Right skew is normal when several tasks are sequentially dependent, even if individual tasks are symmetric.

Related Article:

@RISK: Summary Task Doesn't Sum the Durations of Subtasks.